Alvaredo, Facundo - In: Economics Letters 110 (2011) 3, pp. 274-277
When a very top group of the income distribution, infinitesimal in numbers, owns a finite share S of total income, the Gini coefficient G can be approximated by G*(1 - S)Â +Â S, where G* is the Gini coefficient for the rest of the population. We provide a simple formal proof for this...